Liquid fuel burner



C. A. FRENCH LIQUID FUEL BURNER iled Juvne 15, 1935 May 2l, 1935.

Patented May 2l, 1935 UNITED STATES PATENT OFFICE LIQUID FUEL BURNER Charles A. French, Riverside, Ill.

Application June 15, 1933, Serial No. 675,931

9 Claims.

'I'his invention relates to a liquid fuel burner. More specifically it relates to a vaporizer and burner for gasifying and burning with blue flame combustion heavy hydrocarbon fuels.

The principal object. of the present invention is to provide a burner in which heavy liquid fuels may be instantly vaporized while in suspension in a neutral gas and their vapors afterwards mixed with the proper'amount of air to permitburning with a transparent blue flame.

Another object is to construct a burner to insure that there will be no partial combustion, fuel decomposition, or appreciable condensation in the regular operation of the burner after it is put into operation.

Another object is to-provide a burner of such a construction as to insure a very thorough homogenizing of the combustible mixture before burning.

Another object is to permit a very accurate controlof the temperature of the fuel vapor and air.

Another object is to provide a burner which can be put into full operation in a very short period after starting cold.

These objects and others which will be apparent from the detailed description to follow, are obtained by the construction and operation of a burner as shown in the drawing, in which the single figure is a cross section through a boiler construction of the semi-flash type, of which a burner embodying the invention is a component part.

The drum or casing I 0 is open at its bottom end `and is provided at the upper end with a burned gas outlet II. A combustible gas supply chamber I2 is tted over the bottom of the casing. Said chamber is annular in shape, being provided with a central opening I3. 'I'he upper .Wall of the chamber is perforated to form an annular burner grating I4. The horizontal portion of the burner grating is joined by a burner grating I5 in the form of a portion of a cone with the lower wall of the supply chamber. A cover plate I6 tted over the bottom of the chamber I0 around the opening I3 carries centrally thereof a spray nozzle I1. A conduit I8 communicates with said nozzle'for supplying fuel thereto under pressure. Small openings I9 provide for the admission of a small amount of air through the bottom of the cover member I6 adjacent to the nozzle Il. A spark plug AI8' is fitted into the cover member I6.

A cylindrical vaporizing and receiving chamber 20 is mounted centrally of the casing I0 concentric with respect to the conical grating I5 and the nozzle I'I. The bottom 2I of the vaporizing chamber is spaced vertically above the grating I4 and is flared out at the bottom. A cylindrical screen 22, smaller in diameter than the Vaporizing chamber 20, is mounted within said chamber, spaced from the wall thereof at the lower end. of the chamber, depending a short distance below the bottom end of the chamber. The upper end 0f the vaporizing chamber 20 is restricted at 23, communicating at that point with a chamber 24. An outlet conduit 25 leads from the chamber 24 out through the side wall of the casing I0. A grid 2l is mounted in said conduit. A damper 28 is also mounted in the conduit 25. A main air inlet conduit 29 is restricted at 30 to form a venturi. The conduit 25 has an end portion 26 which surrounds the Venturi portion 30 of the conduit 29. A plurality of openings 3| in the portion 30 provide means for aspirating gases from the conduit 25. A damper 32 is provided in the conduit 29 on the inlet side ahead of the Venturi portion 30. The conduit 29 communicates with the inlet of a pump or fan 33. The outlet or discharge 34 from the fan 33 communicates with an inlet 35 mounted on the gas supply chamber I2.

In the annular space formed between the casing Il) and the vaporizing chamber 20 a plurality of steam generating coils 36 are shown. The connections to and from these coils have not been shown as the boiler itself is of a conventional semiflash type and does not form a part of the present invention.

In the operation of the burner, as above de? scribed, the fan 3,3 is put into operation, thereby drawing gases down the conduit 29 and forcing them into the gas supply chamber I 2 and through the horizontal grating I4 and the grating I5 formed as a portion of a cone. Fuel is supplied under pressure to the conduit I8 and is sprayed upwardly from the nozzle I1 into the vaporizing chamber 20. By means of the spark plug I8 ignition is brought about above the nozzle due to the entrance of air through the openings I9 in the cover member I6. As these small jets of air are in an atmosphere of fuel vapor, a condition known as reciprocal combustion, combustion is readily brought about as this kind of combustion is not sensitive to mixture ratios. In most combustion, a combustible gas is burned in an atmosphere of oxygen containing gas, such as air. When this process is reversed and combustion takes place around a jet of oxygen containing gas in an atmosphere of combustible gas, the combustion has become known in the art as reciprocal combustion. It is not as sensitive to the composition of the combustible gas, as excess is always available, the combustion depending upon the percentage of oxygen in the jet of gas introduced into the atmosphere of combustible gas. As the spray passes outwardly additional air is added through :the grating I5 and the fuel burns with considerable vigor in a bright yellow name which fills the receiving and vaporizing chamber -2!) and the conduit leading therefrom up to the grating 21, where the flame is quenched.

As the amount of fuel sprayed into the vaporizing chamber 20 is considerably more than will be completely burned by the air delivered from the grating I5, the fuel does not burn to complete combustion. The heat of the partial combustion of a portion of the fuel, both radiant and sensible, vaporizes the excess of fuel. The combined products from the vaporization chamber 20 are drawn into the Venturi throat of the conduit 29 and mixed with the main supply of air passing through the conduit. The gases are further mixed by the fan 33 prior to being discharged through the burner gratings. A blue fiame is then obtained above the burner gratings Ill and I5 with complete combustion of the gaseous products.

At the instant of the appearance of the ignitable mixture at the grating I5 it becomes ignited from the burning spray from the nozzle I'I. As soon as the mixture ignites on the grating I4 there is thereafter no air to support combustion in the vaporizing chamber 20 except the small amount coming through the openings I9 in the cover member I6, which is barely enough to support a thin blue flame in the spray. The hot products of combustion from the main burner, however, are drawn into the vaporizing chambensaidproducts, being inert or neutral, extinguishing the ame in the vaporizing chamber until the burner is again put into operation after cooling off. The air valve 32 and the valve 28 may be manipulated particularly when initiating the operation of the burner, to obtain the proper relative mixtures. After the burner has been in operation a few seconds it is no longer necessary to manipulate the air valve 32 except to change the intensity of the fiame in the burner..

'Ihe screen 22 in the form of a cylinder open at the top and bottom in the vaporizing chamber catches any unevaporated fuel falling back out of the vaporizing chamber. surface of fuel exposed on the screen located in the path of the gases passing into the vaporizing chamber brings about rapid vaporization of any fuel on theiscreen. By changing the location of the screen the burner can be operated equally well with the supply chamber and the grating on top instead of underneath, as illustrated.

It is to be understood that applicant has shown and described only a preferred embodiment of his improved liquid fuel burner and that he claims all modifications falling within the scope of the appended claims.

What is claimed is:

1. A liquid fuel vaporizer and burner comprising a combustion chamber, a burner grating positioned over one end of said chamber, a supply chamber in communication with said grating, a fuel -nozzle positioned to deliver fuel at the combustion chamber side of said grating, means for supplying fuel to said nozzle, means for igniting fuel discharged from the nozzle, a receiving chamber positioned in the combustion chamber over the nozzle and rspaced from the grating gas The large amount of moving means, means for delivering air and the gaseous products from the receiving chamber to said means, and means for delivering the mixture from said means to the supply chamber for the grating.

2. A liquid fuel vaporizer and burner comprising a cylindrical combustion chamber, a burner grating positioned over one end 0f said chamber, a supply chamber in communication with said grating, a fuel nozzle positioned to deliver fuel at the combustion chamber side of the grating and mounted axially of the combustion chamber, means for supplying fuel to said nozzle, means for igniting fuel discharged from the nozzle, a cylindrical receiving chamber concentrically mounted with respect to the casing over the nozzle and spaced from the grating, gas moving means, means for delivering air and the gaseous products from the receiving chamber to said means, and means for delivering the mixture from the gas moving means to the grating.

3. A liquid fuel vaporizer and burner comprising a combustion chamber, a burner grating positioned over one end of said chamber, said grating being formed with a central opening therein, a fuel nozzle positioned in said opening, means for supplying fuel to said nozzle, means for igniting fuel discharged from the nozzle, a receiving chamber positioned over the nozzle and a portion of the grating and spaced therefrom, gas moving means, means for delivering air and the gaseous products from the receiving chamber to said means, and means for delivering the mixture from the gas moving means to the supply chamber for the grating.

4. A liquid fuel vaporizer and burner comprising a burner grating, a fuel nozzle positioned to deliver outwardly from the grating on the flame side thereof, means to supply fuel to said nozzle, means for igniting fuel discharged from the nozzle, a. receiving chamber positioned over the nozzle and a portion of the grating, a contact screen secured to the receiving chamber and extending therefrom toward the burner grating, gas moving means, means for delivering air and the gaseous products from the receiving chamber to said means, a supply chamber for the grating, and means for delivering the mixture from the gas moving means to said supply chamber.

5. A liquid fuel vaporizer and burner comprising an annular burner grating, a fuel nozzle positioned centrally of said grating, means for supplying fuel to said nozzle, means for igniting the fuel discharged from the nozzle, a receiving chamber positioned over the grating centrally thereof and overlapping a portion of the grating, gas moving means, means for delivering air and the gaseous products from the receiving chamber to said means, a supply chamber for the burner grating, and means for supplying the mixture from the gas moving means to said supply chamber.

6. A liquid fuel vaporizer and burner comprising an annular burner grating, a center portion of said grating being formed as a portion -oi a cone thereby directing gases discharged therefrom towards the axis of the annulus, a fuel nozzle positioned to deliver vertically from the combustion side of the grating, means for supplying fuel to said nozzle, means for igniting fuel discharged from the nozzle, a receiving chamber positioned over the center of the annulus in overlapping position with respect to the conical portion of the grating and spaced therefrom, gas moving means, means for delivering air and the gaseous products from the receiving chamber to said means, a supply chamber in communication with the burner grating, and means for delivering mixture from the sas moving means to the supply chamber for the grating.

'1. A liquid fuel vaporizer and burner comprising an annular burner grating. a center portion of said grating being formed as a portion of a cone thereby directing gases discharged therefrom towards the axis of the annulus, a fuel noszle positioned to deliver vertically from the flame side of the grating, means for supplying fuel to said nozzle, means for igniting fuel discharged from the nozzle, a receiving chamber positioned over the center of the annulus in overlapping position with respect to the conical portion of the grating and spaced therefrom, a vaporizing screen secured to the receiving chamber andl spaced within the walls thereof, said screen extending adjacent the burner' grating. sas moving means,

means for delivering air and the gaseous products from thc receiving chamber to said means, a supply chamber in communication with the burner grating, and means for delivering air and gaseous products from the gas moving means to the supply chamber for the grating.

8. A liquid fuel vaporizer and burner comprising a combustion chamber. an annular burner grating positioned over the lower end of said chamber, a center portion of the grating being formed as a portion of a cone thereby directing gas towards the axis of the annulus, a supply chamber in communication with the annulus, a cover member for the central opening formed by the annulus, a fuel nozzle positioned in said membertodeliver intothe combustionchamber fromthecenterofthe'openingformedbythe annulus, means for supplying fuel to said nozzle, means for igniting fuel discharged from said nozzle, a receiving chamber centrally positioned in the combustion chamber over the opening formedinthegrating'andspacedthereiromgas moving means, means for delivering air and the gaseous products from the receiving chamber to said gas moving means, and means for delivering the air and gaseous products from the gas mov- ,ing means to the supply chamber for the grating.

9. liquid fuel vaporizer and burner comprising a combustion chamber, an annular burner grating horizontally positioned over the lower end of said chamber, a center portion of the grating being formed as a portion of a cone thereby directing gas towards the axis of the annulus, a supply chamber in communication with the annulus, a cover member for the central opening formed by the annulus, a fuel nomle positioned in said member to deliver vertically into the combustion chamber from the center of the opening 

